Short-term removal of exercise impairs flow-mediated dilation similarly in older and younger adults

Endothelial function is decreased following removal of exercise in young adults. However, whether older adults also experience the same reduction in endothelial function following removal of exercise is not known. The purpose of the study was to investigate the effects of 3 and 5 days of removal of exercise (NOEX3 and NOEX5, respectively) on brachial and popliteal artery flow-mediated dilation (FMD) in older (n = 12, 63.8 ± 2.2 years) and younger (n = 12, 23.9 ± 0.7 years) adults who habitually exercise. %FMD in both the brachial (Old-EX: 7.58 (6.89); NOEX3: 5.58 (7.26); NOEX5: 6.05 (10.43); Young-EX: 7.93 (13.13); NOEX3: 6.57 (12.61); NOEX5: 6.50 (10.74); P = 0.029) and popliteal (Old-EX: 6.56 (8.11); NOEX3: 4.95 (8.52); NOEX5: 4.56 (9.56); Young-EX: 6.15 (8.38); NOEX3: 6.19 (6.72); and NOEX5: 4.77 (6.58); P = 0.013) arteries were reduced following NOEX compared to EX. Peak diameter in both the brachial (Old-EX: 4.02 (0.62); NOEX3: 3.94 (0.62); NOEX5: 3.97 (3.97); Young-EX: 4.40 (0.49); NOEX3: 4.31 (0.52); NOEX5: 4.28 (0.52); P < 0.01) and popliteal (Old-EX 5.74 (1.25); NOEX3: 5.64 (1.28); NOEX5: 5.62 (1.32); Young-EX: 6.07 (0.94); NOEX3: 6.03 (0.87); NOEX5: 5.92 (0.90); P < 0.01) arteries were reduced during NOEX compared to EX. No significant main effects of group or interaction of group by phase were observed for %FMD or peak diameter (P > 0.05). Thus, short-term removal of exercise in older and younger adults reduced brachial and popliteal artery endothelial function. However, no difference in reduction was observed between groups.